Hardware Requirements

Enterprise networks can vary in performance, capacity, protocols, and overall activity. Resource requirements to consider for Nessus deployments include raw network speed, the size of the network being monitored, and the configuration of Nessus.

Scenario

Minimum Recommended Hardware

Nessus scanning up to 50,000 hosts

CPU: 2 dual-core 2 GHz CPU

Memory: 4 GB RAM (8 GB RAM recommended)

Disk space: 30 GB

Nessus scanning more than 50,000 hosts

CPU: 4 dual-core 2 GHz CPU

Memory: 8 GB RAM (16 GB RAM recommended)

Disk space: 30 GB (Additional space may be needed for reporting)

Nessus Manager with up to 10,000 agents

CPU: 4 dual-core, 2GHz CPU

Memory: 16 GB RAM

Disk space: 30 GB (Additional space may be needed for reporting)

Nessus Manager with up to 30,000 agents

CPU: 4 dual-core, 2GHz CPU

Memory: 64 GB RAM

Disk space: 30 GB (Additional space may be needed for reporting)

Nessus Agents

Nessus Agents are designed to be lightweight and to use only minimal system resources. Generally, a Nessus Agent uses 40 MB of RAM (all pageable). A Nessus Agent uses almost no CPU while idle, but is designed to use up to 100% of CPU when available during jobs. However, the Nessus Agent process is a low-priority process and yields the CPU whenever asked.s

The following table outlines the minimum recommended hardware for operating a Nessus Agent. Nessus Agents can be installed on a virtual machine that meets the same requirements specified.

Hardware

Minimum Requirement

Processor

1 Dual-core CPU

Processor Speed

< 1 Ghz

RAM

< 1 GB

Disk Space

< 500 MB

Disk Speed

15-50 IOPS

Virtual Machines

Nessus can be installed on a Virtual Machine that meets the same requirements specified. If your virtual machine is using Network Address Translation (NAT) to reach the network, many of the Nessus vulnerability checks, host enumeration, and operating system identification are negatively affected.